Robotic Surface Treatment  Device

ABSTRACT

A robotic surface treatment device includes at least two wheels, at least two electric motors, wherein one electric motor is connected to one corresponding wheel via a motor shaft, at least two treatment pads, wherein at least one treatment pad is attached to a bottom surface of a corresponding wheel, a main controller positioned on top of and in connection with drive controllers positioned on top of each electric motor, a plurality of sensors integrated in the main controller, and a rechargeable battery connected to the main controller. At least one treatment fluid tank may be positioned on the robotic surface treatment device, and at least one treatment fluid tube may extend from a bottom surface of the treatment fluid tank to a bottom surface of the robotic surface treatment device. The sensors may be laser or acoustic sensors configured to create a boundary line for a treatment area.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/722,183, filed Nov. 4, 2012, the disclosure of which is hereby incorporated in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This disclosure relates generally to a robotic surface treatment device and, more particularly, to a robotic surface treatment device with floor pads rotationally actuated to treat a surface.

2. Description of Related Art

Development of an effective robotic surface cleaning system that can clean any hard surface (e.g. concrete, tiles, vinyl, hardwood, or any combination of these materials) remains difficult to achieve. The state-of-the-art autonomous or tele-operated, robotic or manual (local or controlled) surface cleaning systems that are commercially available for domestic or industrial surface cleaning applications are still ineffective in comparison to common, hand-held mops. These commercially available, wheeled, surface cleaning systems are extremely limited in their ability to properly clean a surface. These systems are incapable of rubbing or pushing the cleaning tools of the system (a cloth or brush) with the requisite amount of pressure necessary for removing dirt, grease, mud, or any other substance from a hard surface. Individuals who have attempted to clean a garage floor covered with engine oil leaking from a car, or mud stuck on a concrete floor from car tires know that the best solution is to scrub the floor with a hand-held scrubber/mop along with soap and water. A manual, hand-held scrubber often works better than a wheel-driven vehicular-type cleaning apparatus because the manual, hand-held scrubber allows the individual using the scrubber to put his/her body weight in action on the scrubber. This application of the body weight to the scrubber is essential to dislodging the dirt and grease that are stuck on the floor. Therefore, the effectiveness of a cleaning apparatus is directly proportional to the amount of force (pressure) the apparatus can exert through the cleaning tool on the surface that needs dirt, grease, etc. to be removed therefrom. It takes a certain amount of friction between the cleaning apparatus and the surface to provide an effective cleaning of the surface.

Each commercially available surface cleaning robot currently on the market work based on similar basic principles. Many of the surface cleaning robots ambulate on wheels, similar to a car. This ensures that there is always a gap between the lower body parts of the cleaning apparatus and the floor. Very few of the surface cleaning robots apply the body weight of the apparatus directly to effectuate surface cleaning similar to the cleaning performed by an individual with a hand-held mop or scrubber. Further, the cleaning tool used by the surface cleaning robot is engaged to clean the floor using a separate mechanism from the surface cleaning robot, which applies minimal pressure necessary for effective cleaning of the floor. Therefore, there is a current need for a robotic surface treatment device that applies the necessary pressure to the treatment surface to provide the requisite friction between the device and the treatment surface to effectuate a proper treatment motion.

SUMMARY OF THE INVENTION

Accordingly, and generally, a robotic surface treatment device and a method of treating a surface using the robotic surface treatment device are provided to address and/or overcome some or all of the deficiencies or drawbacks associated with existing robotic surface treatment devices.

In one embodiment of the invention, a robotic surface treatment device may include at least two wheels, at least two electric motors, at least two treatment pads, a main controller, a plurality of sensors, and at least one rechargeable battery. One electric motor may be connected to one corresponding wheel via a motor shaft. At least one treatment pad may be attached to a bottom surface of a corresponding wheel. The main controller may be positioned on top of and in connection with drive controllers positioned on top of each electric motor. The plurality of sensors may be integrated in the main controller. The rechargeable battery may be connected to the main controller.

At least one treatment fluid tank may be positioned on the top of the robotic surface treatment device. At least one treatment fluid tube may extend from a bottom surface of the treatment fluid tank to a bottom surface of the robotic surface treatment device. The plurality of sensors may be laser or acoustic sensors configured to measure a distance between the robotic surface treatment device and an obstacle. The sensors may be spaced radially about the robotic surface treatment device and may be positioned with equal distances between one another. A treatment fluid tube shut off valve may be positioned in line between the treatment fluid tank and the treatment fluid tube, wherein the treatment fluid tube shut off valve opens upon the robotic surface treatment device activating to treat a surface. The rechargeable battery may be a light weight lithium ion battery. The treatment pads may include an abrasive material configured to scrub, polish, buff, and/or clean a hard surface. Alarms and status indicators may be integrated into the main controller to alert an individual that the rechargeable battery power level is low, that the treatment fluid level is low, and/or that the electric motors have stalled or powered down. The plurality of sensors may be positioned at an angle of approximately 22 degrees apart from one another. The electric motors used to rotate the wheels may be servo motors or stepper motors. At least one weight may be provided on a top surface of the robotic surface treatment device, wherein a rod may be positioned on a top surface of the robotic surface treatment device and the at least one weight may be positioned on the rod. The robotic surface treatment device may be operated through the use of a remote control device.

In another embodiment of the invention, a method of treating a surface using a robotic surface treatment device includes the steps of: providing a robotic surface treatment device as described hereinabove, rotating the wheels of the robotic surface treatment device via rotation of the motor shafts, wherein the motor shafts may be rotated by the electric motors, and increasing the rotational speed of a first wheel comparative to a second wheel, thereby moving the first wheel along a radial trajectory line until the first wheel is positioned in front of the second wheel, wherein the first wheel may be initially positioned at the back of the robotic surface treatment device and the second wheel may be initially positioned at the front of the robotic surface treatment device.

The method may further include the step of using the main controller to create a boundary line of the treating area by using the sensors to determine the distance and coordinates of the treating area. The method may further include the step of recalculating the boundary line of the treating area by using the sensors of the main controller to re-calibrate the distance and coordinates of the treating area. The method may further include the step of walking the robotic surface treatment device along a treating path by repeating the steps described hereinabove at least two times, wherein the wheels may be rotated in an opposite direction after the first wheel has been brought to the front of the robotic surface treatment device. The method may further include the step of treating a circular area by rotating one wheel at one rotational speed and rotation the other wheel at a comparatively faster speed in the same rotational direction. The method may further include the step of providing a treatment fluid in at least one treatment fluid tank positioned on top of the robotic surface treatment device, and at least one treatment fluid tube that may extend from the treatment fluid tank to a bottom surface of the robotic surface treatment device. The method may further include the step of spreading treatment fluid on the treating area and the treatment pads via the treatment fluid tube. The method may further include the step of remotely operating the robotic surface treatment device via a remote control device.

These and other features and characteristics of the robotic surface treatment device, as well as the methods and functions of the related elements of the robotic surface treatment device, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified cross-sectional view of a robotic surface treatment device in accordance with this disclosure.

FIG. 2 is a detailed cross-sectional view of a robotic surface treatment device in accordance with this disclosure.

FIG. 3 is an illustration showing the turning movement of the robotic surface treatment device shown in FIG. 2.

FIG. 4 is an illustration showing the turning movement of the robotic surface treatment device in a direction opposite the one shown in FIG. 3.

FIGS. 5 and 6 are illustrations showing the robotic surface treatment device of FIG. 2 walking forward and backward along a line.

FIG. 7 is an illustration showing the robotic surface treatment device of FIG. 2 rotating in a circle to treat a circular area.

FIG. 8 is an illustration showing how the robotic surface treatment device of FIG. 2 uses its sensors to determine where obstacles are located in the treatment area.

FIG. 9 is an illustration showing the robotic surface treatment device of FIG. 2 using the sensors of the main controller to establish a boundary line for the treatment area.

FIG. 10 is an illustration showing the robotic surface treatment device of FIG. 2 establishing a circular area to treat.

FIG. 11 is an illustration showing a different type of treatment area that includes multiple obstacles including furniture, a closet, and a door.

FIG. 12 is an illustration showing an established boundary line for the robotic surface treatment device and a circular sweep area for treating.

FIG. 13 is an illustration showing a new position for the robotic surface treatment device after a circular area has been treated, wherein the robotic surface treatment device re-calculates a boundary line.

FIG. 14 is an illustration showing the robotic surface treatment device walking along a chosen trajectory line for treating.

FIG. 15 is an illustration showing the robotic surface treatment device spinning in a tight circle for treating a small area.

FIGS. 16 and 17 are illustrations showing a robotic surface treatment device walking along a trajectory line and turning around to walk along a trajectory line in an opposite direction.

FIGS. 18 and 19 are illustrations showing a robotic surface treatment device positioned against an obstacle and establishing a boundary line for treating an area.

DESCRIPTION OF THE INVENTION

For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal”, and derivatives thereof shall relate to the invention as it is oriented in the drawings. However, it is to be understood that the invention may assume alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.

The present invention is directed to, in general, a robotic surface treatment device and, in particular, a robotic surface treatment device with floor pads rotationally actuated to treat a surface. Certain preferred and non-limiting embodiments of the components of the robotic surface treatment device are illustrated in FIGS. 1 and 2. The robotic surface treatment device will first be described in detail followed by a description of a method of using the robotic surface treatment device to treat a surface.

With reference to FIG. 1, a simplified layout of the robotic surface treatment device is illustrated. The robotic surface treatment device 30 includes a plurality of wheels 2 for treating a floor or similar surface by, among other methods, buffing, rubbing, sanding, polishing, or cleaning the surface. In one embodiment of the invention, the robotic surface treatment device 30 includes two separate wheels 2. The wheels 2 are positioned on an undersurface of the robotic surface treatment device 30. Each wheel 2 is rotated by an electric motor 3. Each wheel 2 is rotated by a separate electric motor 3. A motor shaft 4 extends from each electric motor 3 and is connected to each respective wheel 2 to allow the rotation of the motor shaft 4 to effectuate the rotation of the wheel 2.

In one embodiment of the invention, the wheels 2 can be made with metal, such as steel, stainless steel, aluminum, titanium, or any other suitable metal. Additional materials that may be used for the wheels 2 include plastic or any other appropriate hard material. In one preferred embodiment, the wheels 2 are made with a light weight material which helps in optimizing the size of electric motor 3 that is needed to rotate the wheels 2. The lighter the material used for the wheels 2, the smaller the electric motor 3 that is needed because less power is needed to rotate the wheels 2. The optimization of the electric motor 3 will in turn decide the amp-hour (energy storage) requirement of the rechargeable battery 18 that is needed to power the robotic surface treatment device 30.

As shown in FIGS. 1 and 2, each wheel 2 is driven by an individual electric motor 3. Several different types of electric motors may be used to achieve the rotational movement required to rotate the wheels 2 including a stepper motor, a servo motor, a DC motor, an AC motor, a geared motor, or an ungeared motor, among others. The basic principles and operation of the invention is independent of the type and quantity of wheels 2 and electric motors 3 that are used. On the bottom of each wheel 2, a treatment pad 1 is attached for use in treating the surface that the robotic surface treatment device 30 is resting upon. In one embodiment, a Velcro®-type material is glued to a lower surface of each wheel 2. The treatment pad 1 can then be attached to the bottom surface of the wheel 2 by pressing the treatment pad 1 against the Velcro®-type material. The treatment pad 1 may be either made of a cloth material or a paper material, among others. By using the Velcro®-type material to attach the treatment pads 1 to the bottom surface of the wheels 2, the treatment pads 1 may be replaced after every use of the robotic surface treatment device 30 or as deemed necessary by the user of the robotic surface treatment device 30 based upon his/her needs.

As previously mentioned, each wheel 2 is independently driven by its respective electric motor 3. Each electric motor 3 is controlled by an appropriate type of motor controller 7, such as a drive system, based on the type of electric motor that is used to rotate the wheels 2. One or more motor controllers 7 (based on the number of electric motors used for the robotic surface treatment device) will receive the speed, position, and direction commands from a main controller 8. This arrangement gives each electric motor 3 the ability to rotate both in a clock-wise and counter-clockwise direction. Therefore, each electric motor 3 has two degrees of freedom for movement. The speed and direction of each electric motor 3 will determine the resultant movement direction of the robotic surface treatment device 30, but the actual treating operation and effectiveness of the robotic surface treatment device 30 is independent of the movement direction of the robotic surface treatment device 30. The actual treating operation and effectiveness of the robotic surface treatment device 30 is dependent on the factor of friction developed between the treatment surface, the wheels 2, and the treatment pads 1.

With the arrangement used in FIGS. 1 and 2, the entire weight of the robotic surface treatment device 30 sits on the wheels 2 of the apparatus. In the embodiment shown in FIGS. 1 and 2, half of the total weight of the robotic surface treatment device 30 is supported by each wheel 2. In another embodiment, if the robotic surface treatment device 30 were to include three wheels, each wheel would support one third of the total weight of the robotic surface treatment device 30. Therefore, the friction that is developed between the wheels 2 and the floor surface is directly proportional to the weight of the robotic surface treatment device 30 and inversely proportional to the number of wheels 2 on the robotic surface treatment device 30. This embodiment of the invention is the closest a robotic surface treatment device can get to the effectiveness of treating a surface as compared to when a human applies his/her body weight to a mop or scrubber to treat the surface. The weight of the robotic surface treatment device 30 creates the needed friction between the wheels 2 and the floor surface, thereby keeping the robotic surface treatment device 30 in constant contact with the floor surface. In one embodiment of the invention, as shown in FIG. 1, a rod 22 may be attached to a top surface of the robotic surface treatment device 30. Alternatively, the rod 22 can extend through a cavity in the robotic surface treatment device 30. Weights 23 may then be loaded onto the robotic surface treatment device 30 by sliding down the rod 22. In this arrangement, additional weight can be added to the robotic surface treatment device 30, thereby providing the necessary friction between the wheels 2 and the floor surface. It is contemplated that this arrangement would be used when a light weight material is used for the robotic surface treatment device 30. In this instance, the robotic surface treatment device 30 would not provide the necessary weight to provide the needed friction, therefore, the weights 23 could be added to provide additional weight on the top surface of the robotic surface treatment device 30.

In reference to FIG. 2, a more detailed description and illustration of an embodiment of the robotic surface treatment device 30 is shown. As previously mentioned, the robotic surface treatment device 30 includes a plurality of wheels 2 connected to individual electric motors 3 via a motor shaft 4. Attached to the bottom surface of each wheel 2 is a treatment pad 1 for scrubbing and/or wiping the treatment surface. The treatment pads 1, in one embodiment, may be disc-shaped. The treatment pads 1 often correspond to the shape of the bottom surface of the wheels 2. The treatment pads 1 may be made of paper or cloth depending on the surface that must be treated. It is contemplated that the treatment pads 1 may be used for rubbing, polishing, sanding, buffing, and/or cleaning the floor surface. The treatment pads 1 are disposable and may be discarded after every occurrence of floor cleaning or as often as needed by the user of the robotic surface treatment device 30. An abrasive material may also be used for the treatment pads 1 to allow an individual to clean up dirt and grime that may be firmly attached to the treatment surface.

The treatment pads 1 are attached to the bottom surface of the wheels 2. The wheels 2 may be made with light-weight material such as aluminum or alloy metals, plastic, or any similar appropriate material. The wheels 2 are keyed into the motor shafts 4, which effectuates the rotation of the wheels 2 when the motor shafts 4 are rotated by the electric motors 3. Since the treatment pads 1 are attached to the wheels 2, the treatment pads 1 are permitted to rotate as well, thereby treating the surface upon which the robotic surface treatment device 30 rests. This allows the treatment pads 1 to treat the floor surface as the electric motors 3 turn the motor shafts 4, while at the same time the treatment pads 1 do not slip against the surface of the wheels 2 to which they are attached.

The electric motors 3 may be small servo motors, stepper motors, or geared DC motors, among other types of motors. Since the robotic surface treatment device 30 will be powered by a rechargeable battery 18, the motors 3 must be selected with care to ensure that they are high efficiency and have a high starting torque. A high starting torque is important because the robotic surface treatment device 30 needs to start against the floor surface by quickly overcoming the static friction between the treatment pads 1 and the floor surface and then staying in motion by overcoming any dynamic friction that is created. The amount of static friction between the treatment pads 1 and the floor surface is proportional to the weight of the robotic surface treatment device 30 and the roughness of the floor surface. As the electric motors 3 are powered, the motor shafts 4 begin to rotate. The motor shafts 4 are used to transmit power and torque from the electric motors 3 to the wheels 2 of the robotic surface treatment device 30. In this instance, the amount of force required to rotate the wheels 2 against the floor surface is called the load.

A plurality of treatment fluid tubes 5 are positioned adjacent each electric motor 3. The treatment fluid tubes 5 extend vertically along each electric motor 3 with one end positioned above each treatment pad 1. For the effective treatment of a floor surface, it is often necessary to spray/squirt some type of treatment fluid 10 on the floor surface that needs to be treated. In this embodiment of the invention, ordinary soapy water may be used as the treatment fluid. However, it is contemplated that additional types of treatment fluid or liquid detergent, such as wax, may also be used in place of ordinary soapy water to improve the treatment of the floor surface. The treatment fluid 10 is stored in one or more small tanks 11 positioned directly above the treatment fluid tubes 5. Similar to the weights discussed above, the treatment fluid helps to maintain the friction between the wheels 2 of the robotic surface treatment device 30 and the floor surface. When the robotic surface treatment device 30 is in operation, a shut-off valve 21 is activated, allowing the treatment fluid 10 to flow downward through the treatment fluid tube 5 through a gravitational force. The treatment fluid 10 flows to the end of the treatment fluid tube 5 positioned above the wheels 2 and drips onto the treatment pads 1 and/or the surface that requires treating. A treatment fluid chamber cap 12 is positioned over top of an aperture in the treatment fluid chamber 11, and allows an individual to refill the robotic surface treatment device 30 with new treatment fluid 10. The treatment fluid chamber cap 12 must be closed before the robotic surface treatment device 30 can be put into operation.

A drive controller and servo amplifier chamber 6 is positioned above each electric motor 3. Positioned within this chamber 6 and on top of each electric motor 3, is a drive controller and servo amplifier board 7. Each electric motor 3 needs a controller/amplifier board 7 (cards/modules) for controlling and varying the motor speed, direction, and amount of torque that is applied to the wheels 2 of the robotic surface treatment device 30. Each electric motor 3 may be individually controlled by separate controller/amplifier boards 7. It is often the case that small electric motors come prepackaged with built-in driver controllers, which may also be used in conjunction with the robotic surface treatment device 30.

Positioned above the controller/amplifier chamber 6 is a single board computer (SBC) and Programmable Logic Controller (PLC) 8. This SBC/PLC controller 8, for the most part, runs the entire robotic surface treatment device 30. The controller 8 is an electronic circuit board that houses several different components 9, including high-speed microprocessors/microcontrollers, random access memory (RAM), erasable programmable memory (EPROM), clock circuits, bus circuits, various sensors (positional and/or directional), light curtains, fluid level sensors, and other peripheral devices with built-in wireless or radio transmitters/receivers. The SBC/PLC controller 8 performs many tasks, including controlling the robotic surface treatment device 30 by turning it on or off based on an operator's command, whether that is through a local switch mounted on the robotic surface treatment device 30 or through a hand-held remote. The controller 8 is also used to provide sensors that sense barriers/walls/obstacles around the vicinity of the robotic surface treatment device 30 to determine the floor space/area that still needs to be treated. These sensors may include laser or acoustic beams, among others. Path planning is also achieved by the controller 8 to optimize the coverage of the entire treatment area in the shortest amount of time possible. The controller 8 also allows the robotic surface treatment device 30 to receive manual commands from a hand-held radio controller over a radio link or wireless signal from the operator if a remote control or tele-operation mode is selected. The robotic surface treatment device 30 is also capable of using the controller 8 to sense the battery charge level of the rechargeable battery 18 and, in turn, illuminate a “Charging Required” light and/or generate an auto-charging decision for the robotic surface treatment device 30. Likewise, the controller 8 may be used to sense the treatment fluid level in the treatment fluid tanks 11, and can generate an alarm (e.g. light indication) that the treatment fluid 10 needs to be refilled. The controller 8 may also sense when the robotic surface treatment device 30 is stuck or stalled and may illuminate a fault light and/or generate alarm signals. It may also be possible to use the controller 8 to transmit all of the status updates and alarm indications over a wireless link to a home computer or mobile device, such as a smart phone, to notify an individual of the status of the robotic surface treatment device 30. Control of the fluid tube shut-off valve 21 may be achieved by using the controller 8. Determination of the speed and directional relationship between the electric motors 3 in order to control the robotic surface treatment device 30 movement in an efficient manner may be done through use of the controller 8. This ensures that the floor surface is treated in the shortest possible time using the least amount of energy. A final operation that the controller 8 may perform is to generate speed/direction/position commands and send them to the drive controllers and amplifiers boards 7 in order to move the robotic surface treatment device 30 about the floor surface that needs to be treated. The controller 8 may receive feedback from the motor controllers and amplifiers to determine if the robotic surface treatment device 30 is overloaded or in another type of condition.

A negative power supply terminal/lead 13 may be positioned on an upper surface of the SBC/PLC controller 8. A flexible cable 14 connects the negative power supply terminal/lead 13 to a negative power supply terminal/lead 15 on the rechargeable battery 18. Likewise, a positive power supply terminal/lead 20 may be positioned on an upper surface of the SBC/PLC controller 8. A flexible cable 14 connects the positive power supply terminal/lead 20 to a positive power supply terminal/lead 19 on the rechargeable battery 18. The rechargeable battery 18 may be a light weight lithium ion battery or other type of rechargeable battery suitable for use in electric or hybrid cars because these types of batteries are well-known for charge life and a high number of charge/discharge cycles, enhancing the overall battery life. A recharge plug 17 for the rechargeable battery 18 is positioned on top of the rechargeable battery 18 via a pair of flexible cables 16. Each flexible cable 16 connects the recharge plug 17 to the negative power supply terminal/lead 15 and the positive power supply terminal/lead 19 of the rechargeable battery 18, respectively.

With reference to FIGS. 3-7, a method of treating a surface using the robotic surface treatment device 30 is illustrated. In these figures, one embodiment of the invention is shown with two wheels 2 used for treating the floor surface. However, additional embodiments are contemplated where the robotic surface treatment device 30 includes more than two wheels used for treating the floor surface. In FIG. 3, a two-wheeled robotic surface treatment device 30 is shown turning from an East-West direction to a South direction. In this illustration, the wheels A1 and B1 are initially on the same line with one another in a first position. Once the robotic surface treatment device 30 has determined it needs to move, the back wheel B1 and the front wheel A1 rotate in a clockwise direction causing the robotic surface treatment device 30 to turn right. To achieve this rotational movement of the robotic surface treatment device 30 the back wheel B1 rotates at a relatively higher speed as compared to the rotation of the front wheel A1. Since the back wheel B1 rotates at a higher speed, the back wheel B1 is able to cover a larger radial distance than the front wheel A1. This emulates almost a human-like motion, simulating a human as he turns right on his/her legs while sweeping a mop. After the wheels have rotated sufficiently, the new front wheel B2 and the new back wheel A2 are again in line with one another at a new, second position. FIG. 4 shows a similar movement of the robotic surface treatment device 30, however, the robotic surface treatment device 30 moves from an East-West direction to a North direction. During this movement, the wheels rotate in a counter-clockwise rotation to achieve the desired direction of movement. Likewise, the back wheel again rotates at a higher rate than the front wheel, thereby covering a larger radial distance than the front wheel.

It is also contemplated that the wheels 2 of the robotic surface treatment device 30 may rotate in opposite directions during operation. Occasionally, an individual may need to use the robotic surface treatment device 30 to buff, sand, and/or polish a surface. In this operation, it is necessary that the robotic surface treatment device 30 does not move, but rather remains in the same position and rotates the wheels 2 to buff the surface. This can be accomplished by rotating the wheels 2 at the same speed and in opposite directions. This helps to keep the robotic surface treatment device 30 in the same position, but buffs the surface as the wheels 2 rotate opposite one another.

FIG. 5 illustrates a robotic surface treatment device 30 walking from west to east along a trajectory line to treat a surface. During this motion, both the front wheel B and the back wheel A rotate in the same direction. In the first step of the motion, the wheels A and B both rotate in a clockwise direction. In the next step of the motion, the wheels A and B both rotate in a counter-clockwise direction. However, similar to the previous motions described hereinabove, the rotation of the back wheel A is always faster than the rotation of the front wheel B, thereby allowing the back wheel A to cover a larger radial distance than the front wheel B. This rotational difference is necessary to allow the robotic surface treatment device 30 to move forward along the treatment surface. In FIG. 5, the back wheel A rotates in a clockwise direction and follows a radial trajectory path to move from position A1 to position A2. The front wheel B also rotates in a clockwise direction but at a much slower rotational speed. Therefore, the front wheel B moves a much shorter radial distance from position B1 to position B2. In the next step, the direction of rotation for both of the wheels A and B is in a counter-clockwise direction. However, wheel B is now the back wheel and must rotate at a faster speed than the new front wheel A. Wheel B rotates at a faster speed and moves a radial distance from position B2 to position B3, while the new front wheel A rotates at a slower speed and moves a radial distance from position A2 to position A3. The robotic surface treatment device 30 continues these steps, advancing towards an Eastern direction, until the desired treatment surface has been fully treated. Depending on the treatment surface that needs to be treated, the robotic surface treatment device 30 may perform these steps just a few times, or, if the treatment surface is large, the robotic surface treatment device 30 may need to perform these steps multiple times.

FIG. 6 shows a similar movement of the robotic surface treatment device 30 as explained in FIG. 5. However, a backwards movement of the robotic surface treatment device 30 is illustrated. Again, in this movement, both the front wheel and back wheel rotate in the same direction—clockwise in one step and counter-clockwise in another step. Further, as in FIG. 5, the speed of rotation of the back wheel is always faster than the speed of rotation of the front wheel during this movement. Therefore, the back wheel covers a larger radial distance than the front wheel in order to move the robotic surface treatment device 30 forward. In FIG. 6, the back wheel in the first position is wheel A, which is rotated clockwise and follows a radial trajectory to move from point A1 to point A2. Likewise, the front wheel in the first position is wheel B, which is also rotated clockwise and follows a radial trajectory to move from point B1 to point B2. In the next step of movement, the back wheel is now wheel B and the front wheel is wheel A. The direction of rotation for the wheels A and B is now in a counter-clockwise direction. The back wheel B rotates at a faster speed than the front wheel A and travels a radial distance from point B2 to point B3. Likewise, the front wheel A rotates at a slower speed than the back wheel B and travels a radial distance from point A2 to point A3. This process of steps continues until the robotic surface treatment device 30 has moved across the desired treatment surface, advancing in a Western direction.

FIG. 7 illustrates an example of the robotic surface treatment device 30 turning in a circular motion in a clockwise direction to cover a relatively large diametrical distance. By adjusting the rotational speed of the wheels, the robotic surface treatment device 30 may be configured to rotate in a circle to treat a designated area of the treatment surface. In FIG. 7, this is achieved by reducing the rotational speed of the inner wheel and rotating the wheels in the same direction during each step of the movement. Unlike the movements shown in FIGS. 5 and 6, the wheels shown in FIG. 7 rotate in the same direction, thereby causing the robotic surface treatment device 30 to rotate in a circle. In this movement of the robotic surface treatment device 30, however, the outer wheel does not rotate as fast as the back wheel in FIGS. 5 and 6, which allows the robotic surface treatment device 30 to rotate in a circle rather than move forward along a straight path. Further, depending on the speed of rotation of the outer wheel, the robotic surface treatment device 30 can rotate in a smaller space or a larger space. If the outer wheel rotates at a faster speed, a larger space can be treated by the robotic surface treatment device 30. If the outer wheel rotates at a slower speed, a smaller space can be treated by the robotic surface treatment device 30.

In reference to FIGS. 8-19, a method of planning a treatment path using the controller 8 of the robotic surface treatment device 30 is illustrated and described herein. As previously discussed, the controller 8 of the robotic surface treatment device 30 may be equipped with a plurality of acoustic or laser-based distance sensors, wherein each sensor is radially positioned at an angle from each other. Using this arrangement it is possible for the sensors to cover all directions (360 degrees) surrounding the robot. In one embodiment of the invention, sixteen (16) distance sensors are positioned on the robotic surface treatment device 30. Each sensor is positioned at an angle of 22.5 degrees from one another, thereby covering the entire 360 degrees of area surrounding the robotic surface treatment device 30, as shown in FIG. 8. In FIG. 8, the robotic surface treatment device 30 is located at the center of a rectangular space (room) that is completely empty. The distance measurement sensors (laser or acoustic) radiate or propagate in all directions from the center of the robotic surface treatment device 30, thereby measuring the length of distance from the center of the robotic surface treatment device 30 to each wall of the room. As shown further in FIG. 9, the plurality of laser or acoustic sensors project laser or sonar beams onto the walls of the room and measure the corresponding distances. The distances and coordinates of each point where each beam meets each wall are stored in the controller's 8 memory. Next, the controller 8 interpolates an imaginary line (dotted line in FIG. 9) that connects all of the points of intersection between the laser or sonar beams and the walls of the room. This helps the controller 8 to determine what the boundary lines of the treatment surface will be.

After the boundary line has been established by the controller 8, the controller 8 goes through a series of decision-making processes to determine the correct course of action. These decision-making processes including determining whether the area within the boundary line is large enough for the robotic surface treatment device 30 to make any movements at all, whether the area within the boundary line is large enough for the robot to make circular movements, and what the maximum radius of the circle that the robotic surface treatment device 30 can cover first. As shown in FIG. 10, the controller 8 of the robotic surface treatment device 30 then creates an imaginary circle, based on the initial feedback from the distance sensors, which the robotic surface treatment device 30 intends to treat first.

As shown in FIG. 11, treatment areas are rarely devoid of obstacles. Quite often a room will include multiple pieces of furniture, lamps, and similar objects. Using the robotic surface treatment device 30 in this type of atmosphere requires additional planning from the controller 8. The treatment area in FIG. 11 includes a couch, a desk, and a closet, as well as a window and a door. In this situation, the laser or acoustic beams radially point out at different directions in the room, wherein the angle between each sensor is the same. The laser or acoustic beams propagate outwards and come into contact with the walls or furniture, as shown in FIG. 11. As explained above, the distances and coordinates of each of these intersecting points are stored in the controller's 8 memory. Thereafter, a boundary line is created by the controller 8 to calculate the area of the room that the robotic surface treatment device 30 will need to treat.

As shown in FIG. 12 below, the controller 8 goes through a set of decision-making processes to determine what is the best strategy for movement or if any movement at all is possible under the given layout of the room and objects. In FIG. 12, the controller 8 has decided that the robotic surface treatment device 30 should sweep through a circle first. The maximum diameter of the circle is the shortest distance to the wall or obstacle, which avoids any collisions between the robotic surface treatment device 30 and an obstacles. It is critical that once the robotic surface treatment device 30 decides on sweeping through a circle first, there is no need to continue monitoring the distances between the robotic surface treatment device 30 and the walls/barriers/obstacles until it has completed the sweep of the circle. This ensures that the robotic surface treatment device 30 sweeps through the circle as fast as it can. As shown in FIG. 13, once the robotic surface treatment device 30 has completed the current task at hand and it is outside the circle, the robotic surface treatment device 30 once again measures the distances between the robotic surface treatment device 30 and the walls/barriers/obstacles and creates a new boundary line. The controller 8 then goes through the decision-making processes again in order to determine the best possible movement paths for the robotic surface treatment device 30 to take in the shortest amount of time possible.

The robotic surface treatment device 30 is capable of treating an area other than just by rotating in a circle to treat the greatest amount of area possible. As shown in FIG. 14, the controller 8 of the robotic surface treatment device 30 may decide that the best course of movement is to walk through a trajectory line of the treatment area. Using the method of moving the robotic surface treatment device 30 forward along a designated line, the trajectory line can be followed by the robotic surface treatment device 30, thereby treating a large area of the treatment surface. The controller 8 may also decide that it may be better to complete another circular sweep of the treatment area, as shown in FIG. 15. In this instance, the diameter of the circular sweep is smaller than the initial circular sweep and, therefore, the robotic surface treatment device 30 may possibly spin while keeping one of the wheels fixed at the center of the circular sweep. Alternatively, the controller 8 may decide that the best course of action is to simultaneously walk and spin as the robotic surface treatment device 30 moves along a trajectory line, as shown in FIG. 16. Allowing the robotic surface treatment device 30 to simultaneously spin and walk helps the robotic surface treatment device 30 to cover a wider path to treat, but at the same time it takes a longer amount of time to complete the movement. As shown in FIG. 17, once the robotic surface treatment device 30 completes the walk while spinning along the trajectory path, the robotic surface treatment device 30 may turn around and continue its walk and spinning in a direction opposite to the original trajectory path in order to provide a complete sweeping through the targeted treatment area. Once the robotic surface treatment device 30 completes a thorough treating of the target treatment area, the robotic surface treatment device 30 may acquire a new position adjacent to a piece of furniture (obstacle), thereby establishing a new current position using the controller 8, as shown in FIG. 18. As better shown in FIG. 19, the controller 8 and robotic surface treatment device 30 are continuously measuring barrier distances and updating the boundary line of the treatment area that needs to be treated next. Once this new boundary line measurement and computation is complete, the controller 8 plans a new path and movement strategy and executes the same.

While various embodiments of the robotic surface treatment device were provided in the foregoing description, those skilled in the art may make modifications and alterations to these embodiments without departing from the scope and spirit of the invention. For example, it is to be understood that this disclosure contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment. Accordingly, the foregoing description is intended to be illustrative rather than restrictive. The invention described hereinabove is defined by the appended claims and all changes to the invention that fall within the meaning and the range of equivalency of the claims are to be embraced within their scope. 

The invention claimed is:
 1. A robotic surface treatment device, comprising: at least two wheels; at least two electric motors, wherein one electric motor is connected to one corresponding wheel via a motor shaft; at least two treatment pads, wherein at least one treatment pad is attached to a bottom surface of a corresponding wheel; a main controller positioned on top of and in connection with drive controllers positioned on top of each electric motor; a plurality of sensors integrated in the main controller; and at least one rechargeable battery connected to the main controller.
 2. The robotic surface treatment device as claimed in claim 1, further comprising at least one treatment fluid tank positioned on the top of the robotic surface treatment device, and at least one treatment fluid tube extending from a bottom surface of the treatment fluid tank to a bottom surface of the robotic surface treatment device.
 3. The robotic surface treatment device as claimed in claim 2, wherein the plurality of sensors are laser or acoustic sensors configured to measure a distance between the robotic surface treatment device and an obstacle.
 4. The robotic surface treatment device as claimed in claim 3, wherein the sensors are spaced radially about the robotic surface treatment device and are positioned with equal distances between one another.
 5. The robotic surface treatment device as claimed in claim 4, further comprising a treatment fluid tube shut off valve positioned in line between the treatment fluid tank and the treatment fluid tube, wherein the treatment fluid tube shut off valve opens upon the robotic surface treatment device activating to treat a surface.
 6. The robotic surface treatment device as claimed in claim 5, wherein the rechargeable battery is a light weight lithium ion battery.
 7. The robotic surface treatment device as claimed in claim 6, wherein the treatment pads comprise an abrasive material configured to scrub, polish, buff, or clean a hard surface.
 8. The robotic surface treatment device as claimed in claim 7, further comprising alarms and status indicators integrated into the main controller configured to alert an individual that the rechargeable battery power level is low, that the treatment fluid level is low, and/or that the electric motors have stalled or powered down.
 9. The robotic surface treatment device as claimed in claim 8, wherein the electric motors that are used to rotate the wheels are servo motors or stepper motors.
 10. The robotic surface treatment device as claimed in claim 9, wherein the plurality of sensors are positioned at an angle of approximately 22 degrees apart from one another.
 11. The robotic surface treatment device as claimed in claim 5, wherein at least one weight is provided on a top surface of the robotic surface treatment device, wherein a rod is positioned on a top surface of the robotic surface treatment device and the at least one weight is positioned on the rod.
 12. The robotic surface treatment device as claimed in claim 5, wherein the robotic surface treatment device is operated through the use of a remote control device.
 13. A method of treating a surface using a robotic surface treatment device, comprising the steps of: a) providing a robotic surface treatment device, comprising: at least two wheels; at least two electric motors, wherein one electric motor is connected to one corresponding wheel via a motor shaft; and at least two treatment pads, wherein each treatment pad is attached to a bottom surface of a corresponding wheel; b) rotating the wheels of the robotic surface treatment device via rotation of the motor shafts, wherein the motor shafts are rotated by the electric motors, and c) increasing the rotational speed of a first wheel comparative to a second wheel, thereby moving the first wheel along a radial trajectory line until the first wheel is positioned ahead of the second wheel, wherein the first wheel is initially positioned at the back of the robotic surface treatment device and the second wheel is initially positioned at the front of the robotic surface treatment device.
 14. The method of treating a surface as claimed in claim 13, wherein the robotic surface treatment device further comprise a main controller positioned on top of and in connection with drive controllers positioned on top of each electric motor, a plurality of sensors integrated in the main controller, and at least one rechargeable battery connected to the main controller, and wherein the method further comprises the step of using the main controller to create a boundary line of the treatment area by using the sensors to determine the distance and coordinates of the treatment area.
 15. The method of treating a surface as claimed in claim 14, further comprising the step of walking the robotic surface treatment device along a treatment path by repeating steps (b) and (c) at least two times, wherein the wheels are rotated in an opposite direction after the first wheel has been brought to the front of the robotic surface treatment device.
 16. The method of treating a surface as claimed in claim 15, further comprising the step of recalculating the boundary line of the treatment area by using the sensors of the main controller to re-calibrate the distance and coordinates of the treatment area.
 17. The method of treating a surface as claimed in claim 16, further comprising the step of treating a circular area by rotating one wheel at one rotational speed and rotating the other wheel at a comparatively faster speed in the same rotational direction.
 18. The method of treating a surface as claimed in claim 17, further comprising the step of providing treatment fluid in at least one treatment fluid tank positioned on top of the robotic surface treatment device, and providing at least one treatment fluid tube that extends from the treatment fluid tank to a bottom surface of the robotic surface treatment device.
 19. The method of treating a surface as claimed in claim 18, further comprising the step of spreading treatment fluid on the treatment area and the treatment pads via the treatment fluid tube.
 20. The method of treating a surface as claimed in claim 19, further comprising the step of remotely operating the robotic surface treatment device via a remote control device. 